Rockwell Automation 1203 Serial Communications Module Series A - Manual (Page 42)

Chapter 5
Configuration and Interfacing
5-6
The data tables have up to eight areas, each having a different purpose.
1. Parameter Value Read or Write. Reading data from files in this area
will cause the Communications Module to read parameter values from
the SCANport device and send those values as the response to the read
message. Writing data to files in this area will cause the
Communications Module to write that data into SCANport device
parameters.
2. Status of Last Parameter Write. This area is read-only. When read,
the data returned will contain status information from the last parameter
write that was performed by the Communications Module. If no errors
occurred during the write, all of the data returned will be zeros. Read
this area beginning at element number zero.
3. Parameter Read Full. This area is read-only. When read, the data
returned consists of 20 words (40 bytes) of information about each
parameter including scaling, parameter text, units text, minimum,
maximum and default values. When reading this area, set the number of
elements to twenty times the number of parameters to be read.
4. Block Transfer Emulation Area. This area provides a method for
sending and receiving SCANport messages to and from the SCANport
device. This allows the user to perform every SCANport command
supported by the device. The structure of this data table is identical to
that of a block transfer data table for the 1203-GD1, GK1, GM1 RIO
Communications Module.
To send a SCANport message, write data into this area beginning with
element number zero. Allow sufficient time for the SCANport device to
respond to the message and then read the response message from this
area beginning with element number zero.
5. Producer/Consumer Emulation Area. Each element in this area has a
different function. Refer to the DIP switch configuration tables in
Chapter 3 for more information.
– Logic Command/Status. Writing sends a Logic Command to the drive.
Reading supplies the SCANport device Logic Status. Refer to the
manual supplied with the SCANport device for more information.
– Reference/Feedback. Writing sends a reference to the SCANport
device. Reading supplies feedback from the SCANport device. The
meaning of the reference and feedback values are dependent upon the
type of SCANport device.
– Datalink A1. Writing to Datalink A1 sends a value to the parameter
pointed to by the DataIn A1 parameter of the SCANport device.
Reading from Datalink A1 reads the value of the parameter pointed to
by the DataOut A1 parameter of the SCANport device.
– Datalink A2 through Datalink D2 function the same as Datalink A1.